The oxygenation of certain conjugated dienes to form peroxides is known. For example alpha-terpinene (1-methyl,4-isopropylcyclohexa-1,3-diene) has been converted to ascaridole under irradiation. Ergosterol acetate has been converted to a peroxide with irradiation and with various Lewis acids.
Sulfur dioxide is a known Lewis acid and solvent for low temperature reactions. Sulfur dioxide has the disadvantage, however, of polymerizing many olefins to form polysulfones, which are unwanted by-products for many reactions including the ones described herein. In our copending application Ser. No. 862,313, filed Dec. 20, 1977, we described the use of sulfur dioxide to catalyze allylic isomerization or deuteration of certain monoolefins.